BOSTON - Leptin, a molecule linked with obesity, may play a crucial role in predicting poor prognosis from thyroid cancer, at least in the Middle Eastern region of the world, according to data presented at the American Association for Cancer Research Frontiers in Basic Cancer Research Meeting.

"Leptin receptor expression may be a useful molecular marker in predicting the level of aggression of Middle Eastern thyroid cancer that can help guide treatment options and follow-up care," said lead researcher Khawla S. Al-Kuraya, M.D., director of the research center at King Faisal Specialist Hospital and Research Center in Riyadh, Saudi Arabia.

Thyroid cancer is the eighth most common cancer among American women, but the second most common in Saudi Arabian women. This high prevalence is seen in all Gulf Council countries, according to Al-Kuraya.

Al-Kuraya said there is some evidence that thyroid tumors in the Middle East are unique on a molecular level, particularly an increased amplification of the PIK3CA gene.

For the current study, the researchers focused on measuring the level of leptin and its receptor in 536 human thyroid cancer samples. They found overexpression of the leptin receptor in 80 percent of the cases. This overexpression was significantly associated with poor disease survival. Similarly, increased leptin receptor expression was linked with older age, larger tumor size, advanced stage and metastasis. Furthermore, the researchers have conducted numerous in vitro experiments on thyroid cancer cells in the lab and demonstrated that leptin works on the life process of cancer cells by stimulating growth and preventing death.

Leptin is the product of the "obesity gene" and regulates food intake and energy expenditure. Although this is the first study in which researchers have observed its role in thyroid cancer patients, it has previously been implicated in poor prognosis among patients with gastric, endometrial and breast cancer.

Leptin receptor status can be easily assessed with a fine needle biopsy, according to Al-Kuraya.
"This information will be useful in predicting disease aggressiveness and making subsequent treatment decisions about type of surgery, follow-up and iodine dosage," said Al-Kuraya.

The mission of the American Association for Cancer Research is to prevent and cure cancer. Founded in 1907, the AACR is the world's oldest and largest professional organization dedicated to advancing cancer research. The membership includes 30,000 basic, translational and clinical researchers; health care professionals; and cancer survivors and advocates in the United States and nearly 90 other countries. The AACR marshals the full spectrum of expertise from the cancer community to accelerate progress in the prevention, diagnosis and treatment of cancer through high-quality scientific and educational programs. It funds innovative, meritorious research grants, research fellowship and career development awards. The AACR Annual Meeting attracts more than 16,000 participants who share the latest discoveries and developments in the field. Special conferences throughout the year present novel data across a wide variety of topics in cancer research, treatment and patient care. The AACR publishes six major peer-reviewed journals: Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; Cancer Epidemiology, Biomarkers & Prevention; and Cancer Prevention Research. The AACR also publishes CR, a magazine for cancer survivors and their families, patient advocates, physicians and scientists. CR provides a forum for sharing essential, evidence-based information and perspectives on progress in cancer research, survivorship and advocacy.

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